Surface charge induced modifications of the structure and dynamics of mixed dipolar liquids at solid--liquid interfaces: A molecular dynamics simulation study

Molecular dynamics simulations are carried out to investigate the structural and dynamical properties of binary Stockmayer liquids near charged solid surfaces at varying surface charge density. The two solvent components differ widely in their polarity. The dipolar mixtures are formed at varying composition and the properties of the interfacial molecules are calculated in terms of several equilibrium and dynamical quantities such as the number density and polarization profiles, electrostriction at surfaces, linear and angular velocity autocorrelation functions, perpendicular (z) and parallel (x,y) components of translational diffusion tensors and rotational diffusion coefficients. The extent of selective adsorption of one species against the other at the surfaces is investigated as a function of surface charge density and composition and its effects on translational and rotational diffusion of interfacial molecules are discussed. The dynamical properties of the interfaces are also compared with those of the bulk. © 2000 American Institute of Physics.